FUNCTION: [Summary is not available for the mouse gene. This summary is for the human ortholog.] Dyneins are a group of microtubule-activated ATPases that function as molecular motors. They are divided into two subgroups of axonemal and cytoplasmic dyneins. The cytoplasmic dyneins function in intracellular motility, including retrograde axonal transport, protein sorting, organelle movement, and spindle dynamics. Molecules of conventional cytoplasmic dynein are comprised of 2 heavy chain polypeptides and a number of intermediate and light chains.This gene encodes a member of the cytoplasmic dynein heavy chain family. [provided by RefSeq, Oct 2008] PHENOTYPE: Mice homozygous for either the Cra1 or Loa ENU mutation exhibit neonatal lethality with reduced anterior horn cell number, abnormal motor neuron innervation, neuronal inclusions, and abnormal axonal transport. Heterozygotes display motor neuron degeneration and muscle spasms. [provided by MGI curators]